Just had a pay cut? Spurned by your lover? Can't get over the fact that the little guy won American Idol?
When the initial gut-wrenching surge of anxiety subsides you may find yourself reaching for the chocolate brownies. This is because when something stresses you out it triggers a two stage reaction.
First, the fight or flight response: your heart speeds up, your muscles tense, your digestive system shuts down - all so you can focus on attacking your stress object or running away. (If someone offered you a brownie at this point you'd probably punch them in the face.)
But next comes a slower response: your adrenal gland unleashes a nifty little hormone called cortisol. Cortisol helps you use energy more efficiently by telling your body to start making glucose and burning up fat.
Unfortunately, it may also tell you to get to the nearest vending machine and load up on candy.
How do we know this? Well it's definitely true for rats. When you stress them out by pinching their tails or injecting cortisol they drink more condensed milk or sucrose.
Humans are harder to study - they won't let you pinch them and they might not drink condensed milk for you even if they want to. But in one study, women who released the most cortisol during an onslaught of stressful tasks ate more snacks than other women who only released a small amount.
Interestingly enough, the cortisol effect only works with tasty, high fat foods. Humans picked chocolate bars rather than rice cakes in the stressful task study. Rats won't eat more boring old lab chow however much you bug them. And back in the real world, people who say they're stressed in general have a diet that's higher in fat.
The diet difference could partly be because life demands force the stressed masses to rely on more high-calorie convenience foods. But it also makes good evolutionary sense to stockpile calories in difficult times - you never know when some extra energy might come in handy.
Of course comfort-eating needn't necessarily be the bad thing it's made out to be. As my unremittingly optimistic grandmother always says - a little bit of what you fancy does you good. And one study in Taiwan found that children who ate junk food were fatter, but happier. Isn't it worth gaining a few pounds to feel a little more cheerful all round?
If eating fries and fritters was the only way to be happy I would say, categorically, yes. But new research suggests that cortisol actually increases appetite by acting more generally on emotional brain areas, with the effect of increasing the desirability of all pleasurable activities - not just stuffing one's face with food.
The message? Eating might be the way you usually find your solace, but it never hurts to try something different instead.
Remember that the next time someone tries to pinch your tail.
